The present invention relates in general to the scrubbing of flue gases from furnaces and other sources of such gases, and in particular to a new and useful method and apparatus of scrubbing acid gases such as SO.sub.2 and HCl from flue gases using a moving bed of granular scrubbing material.
A moving bed of scrubbing material for removing sulfur oxides from flue gases is disclosed in U.S. Pat. No. 3,976,747. Before passing the flue gases through the moving bed, the flue gases are conditioned by adding water thereto. The water in the flue gases then condenses on particles of the scrubbing material in the bed for increasing the rate of reaction between the sulfur oxides and particles of the scrubbing material.
U.S. Pat. Nos. 4,663,136 and 4,764,348 disclose a similar process which, however, utilizes fixed beds of the scrubbing material, to which the flue gases are supplied. The scrubbing material is cool so that water in the flue gas condenses on particles of the scrubbing material.
A need remains for an improved method and apparatus for scrubbing acid gases such as sulfur oxides from flue gases which is efficient and economical, and in particular a method and apparatus which can be retrofit into existing plants in a convenient and economical manner.